Swapping in a 97 XJ AW4, need tips and advice

[Airborne Janitor]

Going to be replacing the busted AW4 in my 89 MJ. I have a complete engine/tranny/t-case from a 97 XJ. I am NOT swapping motors, just the transmission and case. I know I need to keep the 97 throttle valve cable, 89 NSS and TCM. I am also aware of the tailshaft differences and swapping the mechanical speedo in place of the electronic speedo.

 

From what I gather I will have to splice wires since the connectors are different on both the transmissions. Does anyone have any additional info regarding this or the appropriate wiring diagrams?

 

I am assuming I can just swap over the torque converter from the 97?

 

My MJ is a column shift, I'm assuming the transmission shift cable/bracket should just bolt right up to the 97 AW4?

 

I should keep the 89 CPS and flexplate correct?

 

Also are there any issues pulling out the vacuum lines for the old case/front axle since I won't need them anymore?

 

Finally, I will be replacing the seal between the t-case and tranny, are there any other serviceable items I should consider replacing as well while everything is apart? I will be replacing the filter/screen on the tranny.

 

Thanks.

[ScottJeep]

All the differences covered here. 

http://www.naxja.org/forum/showthread.php?t=1053970

 

The shift levers are different between the XJ ( console ) vs your MJ ( column ). You will need to move the lever over if you are keeping the column shift.

Be careful and hit the nut hold on the lever with some PB Blaster or your penetrant of choice before attempting to remove said nut.

The end of the shaft where the lever attaches is known to snap off with few option for repair ( the shaft runs completely through the transmission). 

[Airborne Janitor]

Thanks for the reply. I went through all 30+ pages of that thread a month ago believe it or not, but it didn't answer my specific questions regarding the 97 wire splicing and swapping into a column shift rig. After your post I inspected the levers on both transmissions and you are indeed correct, thanks for the heads up, could have easily over looked that.

[Airborne Janitor]

Latest update, got both transmissions pulled, 97 above and 89 below. They look pretty identical, they even have the same numbers/stampings.

 

 

The big difference is the output spline count and the wiring. There is this additional connector on the 89 AW4 that was hiding behind the transfercase linkage bracket. Mine was unplugged, perhaps it's always been that way?

 

 

And of course the harness connectors. The 97 has five wires/pins:

 

 

And the 89 has seven wires/pins:

 

 

So I gotta figure out how to splice the 89 wiring into the 97 AW4. Since the 89 had that additional unused plug (2 wires) I'm assuming where the additional 2 pins on the connector are for.

 

As for the transfercase, the 97 which does not have the vacuum connector, but does have the part-time/4x4 light switch and is 23 spline.

 

 

The 89 which had a mechanical speedo sensor and vacuum operated crap.

 

 

The vacuum wiring harness completely removed:

 

[Airborne Janitor]

So school me on this, for Renix rigs that have the vacuum 4x4 system, is that responsible for turning on the 4x4/part-time light on the dash when the case is engaged? Anyone know what that additional unused connector on the 89 AW4 is for, perhaps the part-time light? Will be studying wiring diagrams tonight.

[gogmorgo]

The extra connector is for the np242. Instead of the vacuum crap there's an electric switch that grounds the full-time and part-time 4x4 lights.

In contrast the part-time light on a 231-equipped jeep with the vacuum crap is grounded by a vacuum switch, I think in the engine bay somewhere on your '89, although on my '91 it's built into the CAD housing. When I say the lights are grounded what I mean is exactly that, they have constant power with the key on and the switches are on the ground side.